During the harvesting of trees, the branches must be removed from the trunks of the trees before the logs can be easily transported and stacked. Efficient harvesting demands rather quick removal of the branches from the trunks. Although delimbing machines for use with a single tree and machines for use with multiple trees are known, the latter machines which can delimb a number of trunks at a time are of most interest.
U.S. Pat. Nos. 3,805,858 and 3,882,913 show a machine mounted on the end of a truck wherein a lower beam protrudes generally horizontally from the rear of the vehicle, while an upper beam is movable pivotally so as to provide for placement of trunks on the lower beam before delimbing. This machine with its two beams pivotally separated like a giant mouth must be backed toward a group of tree trunks held by a second vehicle. When the trunks have been located on the lower beam, the upper beam is lowered and the trunks are pulled between the upper and lower beams. Operation of the machine would seem to be difficult and time consuming due to the procedure required for initially arranging the trunks on the lower beam.
U.S. Pat. No. 4,147,190 shows a delimber whereby a skidder vehicle tows a small group of trees along the ground toward the machine. The skidder passes on the side of the machine which is structurally open. As soon as the skidder has passed, it swings rapidly in the direction of the machine to direct the tree trunks skidding along the ground into the machine. The trunks are pulled up a ramp and between cutter bars. When the cutter bars have been appropriately located with respect to the trunks, a winch on the skidder pulls the trees through the delimbing machine. The problem, it would appear, with this machine is that the ends of the tree trunks must be plowed through the ground and appropriately maneuvered to be pulled into the delimber machine. It would seem that it would be particularly frustrating if some of the tree trunks were properly aligned, while others just missed the machine.
U.S. Pat. No. 4,440,202 shows yet another tree delimber machine wherein the trunk ends are abutted against a stop while the other ends of the trees are maneuvered with a crane into cellular openings in a grid-like cutter. The cutter is moved longitudinally along the tree trunks to slice off the tree limbs. Although this machine can handle several trees at a time, the individual alignment of various trees and the placing of a trunk end in the grid-like cutter would appear to be a time consuming operation.
The common problem with all these delimber machines is the difficulty in initially positioning multiple tree trunks with respect to the machine. The present invention solves that problem and functions otherwise efficiently to delimb numerous trees at once.